This is an application for a Midcareer Investigator Award in Patient- Oriented Research (K24) grant. The applicant is a psychiatrist/biophysicist who directs the McLean Hospital Brain Imaging Center (BIC). The BIC is an extremely active and productive research center with a major research interest in the development and rapid application of promising new magnetic resonance techniques for better understanding the acute and chronic effects of drugs of abuse on the brain. During the last 12 months, a total of 650 NIDA-funded research scans were completed by BIC investigators. The PI has been a NIDA-funded investigator since 1994 and he currently provides mentoring for 13 talented scientists, five of whom have NIH-funded Mentored Career Development Awards. This application is a request for five years of funding to relieve the candidate of a significant amount of administrative responsibility so that he can devote a greater effort to conducting research, growing professionally, and fostering the careers of the next generation of clinician scientists in the unique field of brain imaging and drug abuse. Funding of this K24 proposal, which will support 50% of the candidate's effort, would allow the PI to focus his research on a select group of the candidate's funded drug abuse research projects, to spend more time working with young investigators, and to obtain additional training in the areas of biomedical engineering, computing, and statistics. McLean Hospital has committed to hiring an administrator for the BIC to reduce the candidate's administrative responsibilities and to hire two additional faculty members to take over the candidate's responsibilities for research studies which do not involve drug abuse. In addition to the mentoring and training activities supported by the K24 award, the PI proposes to devote the remaining 50% of his effort to NBA-funded research grants on which he is PI: Magnetic Resonance, EEG, and Behavior After Cocaine (DA09448); High Field MR Research in Drug Abuse: A Bioengineering Partnership (DA14178); and on which he is Col: MR Spectroscopic Imaging During Methadone Maintenance (DA11321); and Medication Development for Cocaine Abuse: CDP-choline (DA11098).